Antimicrobial blue light reduced the number and size of colonies of Pseudomonas aeruginosa.

The biofilm formation ability of Pseudomonas aeruginosa was reduced after antimicrobial blue light treatment.

Antimicrobial blue light affected the utilization of various nutrients by Pseudomonas aeruginosa.

Antimicrobial blue light activated the glyoxylate cycle and denitrification pathway in Pseudomonas aeruginosa.

This study aimed to systematically explore the growth-inhibitory efficacy of Antimicrobial Blue Light (aBL) against Pseudomonas aeruginosa and comprehensively elucidate its molecular mechanisms of action.

A network pharmacology framework was employed to evaluate the therapeutic potential of aBL. Experimental assessments included: Bacterial proliferation analysis: Quantification of inhibitory effects via colony-forming unit (CFU) counts and colony area. Kinetic profiling: Analyze the growth curve of bacteria to determine aBL-mediated bactericidal dynamics. Biofilm quantification: Crystal violet staining to assess biofilm formation capacity under aBL exposure. Mechanistic investigation: RNA sequencing and transcription factor prediction to identify molecular pathways modulated by aBL. Validation: Quantitative reverse transcription PCR (qRT-PCR) was performed on both laboratory and clinical strains to confirm transcriptional regulation of key targets.

1. aBL significantly inhibited the growth of P. aeruginosa, as evidenced by a reduction in colony count and area. The bacterial growth rate decreased, ultimately leading to a marked decline in bacterial density; 2. RNA-seq results revealed 297 upregulated genes and 247 downregulated genes in the aBL group. GO enrichment analysis indicated that differentially expressed genes were concentrated in biological processes such as oxidoreductase activity and nucleoside phosphate binding. KEGG enrichment analysis demonstrated significant enrichment in pathways including ABC transporters, two-component systems, carbon metabolism, and quorum sensing; 3. qPCR validation results indicate that aBL treatment significantly upregulates the expression of the glyoxylate cycle genes glcE and glcF, as well as the denitrification pathway genes nirM, nosD, and nosZ, suggesting that aBL activated the relevant metabolic pathways.

1. aBL effectively inhibited the growth of P. aeruginosa and reduced its biofilm formation; 2. aBL activated the glyoxylate cycle and denitrification pathways, thereby influencing bacterial metabolic activity.

This study provides experimental evidence and theoretical support for employing aBL as an adjunctive therapeutic strategy for localised clinical infection control.

Pseudomonas aeruginosa

Biofilm

Antimicrobial blue light

Denitrification

Glyoxylate cycle

© 2025 The Authors. Published by Elsevier B.V.